Mobile Home, Off-Highway Vehicle or Vessel. The form also documents the sale and is the legal receipt.An RV Bill of Sale is a legal document that serves as proof of the sale and transfer of ownership of a recreational vehicle (RV) from a seller to a buyer. Motor vehicles, vessels, mobile homes and trailers must be registered at the point of purchase and a certificate of title issued as proof of ownership. This document serves as proof of ownership and allows the seller to report the sale to the DMV. The form includes the details of the vehicle. Customize a bill of sale document to transfer ownership of a vehicle, boat, firearm, or other item. In the state of Florida, a form HSMV 82050 is a notice of sale.